Set oven to 375F, 190 °C Gas 5. Grease & line a 2lb loaf pan with a long strip of waxed paper. Fry onion & celery in margarine for 7 minutes then add the garlic & coo a further 3 minutes. Remove from heat & add remaining ingredients. Season well with salt & pepper. Turn mixture into waxed paper lined loaf pan. Cover with foil & bake for 1 hour. Remove foil & cook another 15 minutes until the loaf is firm in the centre. Remove loaf from the oven & allow to stand 3 to 4 minutes. Loosen the edges with a knife & turn loaf out onto a serving platter. Garnish with tomato, lemon & parsley.